I began porting the dba module to Drupal 7 as an opportunity to learn more about the new database abstraction layer. In this upcoming Drupal release, our database layer is now built upon the PHP Data Objects (PDO) data-access abstraction layer, introducing new syntax and symantecs into writing queries with Drupal. A powerful new query builder makes it possible to easily write queries that run on any database type supported by Drupal, currently including MySQL, PostgreSQL and SQLite.

The dba module was always intended to be a useful tool for any database administrator, and toward that end I have recently merged in mysqlreport functionality which utilizes MySQL's server statistics to offer an overview of server health and performance. As an enhancement, I also merged in the knowledge shared in this earlier Tag1 Consulting article, so now problem areas detected in the mysqlreport output are automatically highlighted along with some useful help text offering tips on better tuning your database.

Join a talented and intelligent team. Become an expert in administering open source databases and operating systems, tuning the entire LAMP stack for optimal performance. Participate in active and lively open source communities. Work with and learn from experts in the field, building and optimizing the infrastructures and software behind successful and popular websites.

At the beginning of 2009, I was hired by Tag1 Consulting as Jeremy Andrews' full time partner. A decidedly questionable decision on his part, but a great change for me! I used to work at the Open Source Lab at Oregon State University and I am currently the sysadmin for drupal.org. Working at the OSL and drupal.org spoiled me, I'll be completely honest about that. I got used to working with interesting new technologies and consistently pushing the limits of my knowledge.

We at Tag1 have used the Cacti Memcache templates many times. (http://dealnews.com/developers/cacti/memcached.html) They have become a staple for us and many others. However, we and one of our clients have had issues making them work for monitoring multiple Memcache instances (running on different ports) on the same host. It is possible to make this work with the vanilla templates, but it is a bit difficult.

I've had the opportunity in the last few days to use quite a few cool little utilities that made my life considerably easier. I've known about most of them for awhile, but discovered some new tools or new uses for old tools and wanted to share two of them.

I recently joined Tag1 Consulting full time. My main project since I joined was building up our monitoring infrastructure. My personal goal being world domination, but first the best monitoring system I can build. Baby steps...baby steps. For quite awhile now, I've used the monitoring system we built at the Open Source Lab to detect and diagnose problems with drupal.org, apache.org, kerneltrap.org and many more Free Software projects hosted at the lab. These experiences convinced me of the absolute necessity of a robust monitoring system.

Description:
The drupal_lookup_path function unnecessarily counts all rows of the url_alias table to determine if any aliases are defined. This can be expensive on a transactional database such as MySQL with the InnoDB Storage Engine or PostgreSQL when a website has a lot of aliases. This patch modifies the query to always only return one row, possible because any existing pid will be greater than 0. If no aliases are defined, it will return 0.

Status:
This patch has not been merged into any release of Drupal.

Patch

Until recently, I was a student employee at the Oregon State University Open Source Lab. My career there ended, like many, with that painful process known as graduation. I got invaluable experience at the lab, not the least of which being the knowledge gained as their main (only) database administrator. One of my great pleasures in that position, was learning how to configure MySQL replication and manage clusters of replicating database servers. Even the simple case of a single master and a single slave has its edge cases.

I have completed a rough draft of the first chapter of "Drupal Performance and Scalability". The first chapter of this online book is divided into four sections, the first of which focuses on the importance of fully defining your performance and scalability goals, helping you to identify what you need to accomplish and how to set concrete and attainable goals. The second section discusses monitoring and measuring your ongoing progress, helping you decide what you need to monitor, and how to monitor it. The third section stresses the importance of making regular backups, discussing what needs to be backed up, and offering example scripts for backing up your entire website, including the database. Finally, the fourth section takes an in depth look at using revision control tools to manage your website, providing useful recipes showing how Git can track changes to your website, helping you update to new releases and push those updates into production.

It is important to realize that this is a rough draft, and as such it may contain spelling or grammatical errors, it may be missing key points, and the writing style may not be very polished. However, the book has to start somewhere, and this is the first step toward the end goal of publishing a useful and freely available online resource. I welcome all criticisms, suggestions and feedback. If you find errors in the text or have specific comments, you can help with this writing project by posting your feedback on the appropriate page. The current status of this project is tracked here.

In previous search benchmarks, I utilized random content generated with Drupal's devel module. In these latest benchmarks, I used an actual sanitized copy of the Drupal.org community website database, with email addresses and passwords removed. The first tests were intended to confirm that Xapian continues to perform well with large amounts of actual data. Additional tests were performed to measure the effect of various MySQL tunings and configurations. The following data was derived from several hundred benchmarks run on an Amazon AWS instance over the past week using the SearchBench module.

These tests confirm that Xapian continues to offer better search performance than Drupal's core search module. Contrary to popular belief, the data also shows that using the InnoDB storage engine for search tables significantly outperforms using the MyISAM storage engine for search tables, especially when your database server has sufficient RAM. The data also confirms that allocating additional RAM for MySQL's temporary tables can also improve search performance.